What year of high school are you in?
Some universities will sometimes ask for and look at mid term senior year grades. Some will not. If you are still a junior, then having better grades for your junior year can help quite a bit when it comes to college admissions.
Regardless, you will help yourself quite a bit if you start putting in an effort and improving your grades starting today, and continuing as long as you are taking any classes. If nothing else this will help you to be better prepared when you do get to college.
And a 1480 SAT score is very good for the vast majority of universities.